Seed germination and seedling vigor of weevil-damaged acorns of red oak
Seed germination and seedling vigor of weevil-damaged acorns of red oak
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DOI：
10.1139/x09-079
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发表时间：
2009-08-01
影响因子：
2.2
通讯作者：
McCarthy, Brian C.
中科院分区：
文献类型：
--
作者：
Lombardo, Jeffrey A.;McCarthy, Brian C.
橡子象甲（鞘翅目：橡子象甲科）是美国东部阔叶林地区常见的橡子捕食者。我们研究了种子发芽率，以及幼苗的物理特性，来自两个象鼻虫损害和健全的橡子红橡树（Quercus rubra L.）以确定象鼻虫破坏是否影响幼苗活力。种子在温室条件下生长8周。X射线成像被用作确定种子发芽前的条件的非破坏性方法。合并后的数据集显示，发芽率从86%的声音橡子减少到26%的象鼻虫损坏。七个幼苗指标进行了评估，从声音和那些从象鼻虫损害橡子之间的差异。在这些指标中，叶片数、总叶片数、根颈直径、新梢长度和干重差异显著（P < 0.05）。两个变量，根长和芽直径，没有显着差异。早期分配资源建立根系可能解释了这些发现。由于减少茎高和叶数，幼苗从象鼻虫损害橡子可能是竞争力较低的森林林下比那些健全橡子。
Acorn weevils (Coleoptera: Curculionidae) are well-known predators of oak acorns in the eastern hardwood forest region of the United States. We examined the germination percentage of seeds, as well as the physical characteristics of seedlings, originating from both weevil-damaged and sound acorns of red oak (Quercus rubra L.) to determine if weevil depredation impacts seedling vigor. Seeds were grown under greenhouse conditions for a period of 8 weeks. X-ray imaging was used as a nondestructive method for determining seed condition prior to germination. The combined data set showed a reduction in germination percentage from 86% for sound acorns to 26% for those damaged by weevils. Seven seedling metrics were evaluated for differences between seedlings originating from sound and those from weevil-damaged acorns. Of these metrics, the number of leaf flushes, total number of leaves, root collar diameter, shoot length, and dry mass were significantly (P < 0.05) different. Two variables, root length and shoot diameter, were not significantly different. Early allocation of resources to root establishment likely explains these findings. Because of reduced stem height and leaf number, seedlings from weevil-damaged acorns are likely to be less competitive in the forest understory than those from sound acorns.